From 80f59dd749ae3986d659a8c5b3c69942a2f90a8f Mon Sep 17 00:00:00 2001
From: Sebastian Krzyszkowiak <dos@dosowisko.net>
Date: Mon, 23 Apr 2018 03:24:13 +0200
Subject: [PATCH] tween: add function to just interpolate the value, without
 using Tween object

---
 src/tween.c | 16 ++++++++++++----
 src/tween.h |  1 +
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/tween.c b/src/tween.c
index d1abfd7..c9a3d59 100644
--- a/src/tween.c
+++ b/src/tween.c
@@ -264,9 +264,14 @@ double GetTweenPosition(struct Tween* tween) {
 	return tween->pos / tween->duration;
 }
 
-double GetTweenInterpolation(struct Tween* tween) {
-	double pos = GetTweenPosition(tween);
-	switch (tween->style) {
+double Interpolate(double pos, TWEEN_STYLE style) {
+	if (pos < 0.0) {
+		pos = 0.0;
+	}
+	if (pos > 1.0) {
+		pos = 1.0;
+	}
+	switch (style) {
 		case TWEEN_STYLE_LINEAR:
 			return LinearInterpolation(pos);
 		case TWEEN_STYLE_QUADRATIC_IN:
@@ -330,7 +335,10 @@ double GetTweenInterpolation(struct Tween* tween) {
 		case TWEEN_STYLE_BOUNCE_IN_OUT:
 			return BounceEaseInOut(pos);
 	}
-	return pos;
+}
+
+double GetTweenInterpolation(struct Tween* tween) {
+	return Interpolate(GetTweenPosition(tween), tween->style);
 }
 
 double GetTweenValue(struct Tween* tween) {
diff --git a/src/tween.h b/src/tween.h
index 7387a9c..6cdb5b7 100644
--- a/src/tween.h
+++ b/src/tween.h
@@ -84,5 +84,6 @@ double GetTweenPosition(struct Tween* tween);
 double GetTweenInterpolation(struct Tween* tween);
 double GetTweenValue(struct Tween* tween);
 void UpdateTween(struct Tween* tween, double delta);
+double Interpolate(double pos, TWEEN_STYLE style);
 
 #endif